Auxiliary starter device for air conditioner compressor

ABSTRACT

This invention is directed to a factory-assembled device which provides field installation personnel with accurate, quickly installed means for adding extra capacitance to the starting circuit of the electric motor for the fluid compressor of an air conditioner.

United States Patent James L. Ballard Tyler, Tex.

July 29, 1970 Nov. 9, 1971 General Electric Company Inventor Appl. No.Filed Patented Assignee AUXILIARY STARTER DEVICE FOR AIR CONDITIONERCOMPRESSOR 4 Claims, 4 Drawing Figs.

vs. C] 307/149, 310/71, 318/221 Int. Cl H02j 1/00 Field of Search310/66, 71;

[56] References Cited UNITED STATES PATENTS 2,181,734 11/1939 Mooney r.318/221 D 3,350,586 10/1967 Otto 310/71 2,338,515 1/1944 Johns 318/221 APrimary Examiner- Herman J. Hohauser Attorneys-Harry B. O'Donnell, III,Francis H. Boos, Frank L.

Neuhauser, Oscar B. Waddell and Joseph B. Forman ABSTRACT: Thisinvention is directed to a factory-assembled device which provides fieldinstallation personnel with accurate, quickly installed means for addingextra capacitance to the starting circuit of the electric motor for thefluid compressor of an air conditioner.

PAIENTEDuov 9 ml 3, 19,641

sum 1 or 2 INVENTOR. J'AME L. BALLARD H \S ATTORNEV PATENTEnunv 9 ISTISHEET 2 OF 2 H 5 -ATTORNEY AUXILIARY STARTER DEVICE FOR AIR CONDITIONERCOMPRESSOR BACKGROUND OF THE INVENTION This invention is related to airconditioners and, more particularly, to an auxiliary starter device forthe fluid compressor of a central air conditioner of the so-called splitsystem variety.

Split system air conditioner cooling units generally comprise two basicsections, one of which is referred to as the evaporator section that ismounted within the building to be cooled, and the other of which isreferred to as the condensercompressor section that is housed within acabinet that is mounted outside of the building. The evaporator,condenser and compressor are, of course, fluid-interconnected in awellknown manner by conduit means.

Because of various reasons, e.g. exposure to the weather, etc., it isusually necessary to replace the condenser-compressor section longbefore the evaporator section. Many such split-system air conditionercooling units have been in service in the field for several years andnow require replacement of their condenser-compressor sections. However,most of the evaporator sections of these older central air conditionerunits differ from modern evaporator sections in that they employedexpansion valve means to expand the liquid refrigerant fluid into agaseous state prior to its entry into the evaporator coil from thecondenser-compressor section, rather than the capillary means presentlyused for this purpose. And, if one at- .-tempts interconnection of amodern replacement condensercompressor section with one of these oldevaporator sections, he is almost certain to find that thecapacitanceprovided in the starting circuit for the electric motor ofthe fluid compressor of the modern replacement condenser-compressorsection, as supplied from the factory, is then insufficient to permitstarting of the replacement compressor.

Heretofore, various schemes have been improvised by field installationpersonnel in an effort to overcome the aforenoted incompatibilitybetween the modern replacement compressor and the old evaporator sectionwith which it is sought to be coupled. However, these prior art methodshave required field rewiring of the replacement compressor motorstarting circuit. And, such field rewiring has presented problems, e.g.use of oversized auxiliary capacitors, failure to provide means fordisconnecting the auxiliary capacitor from the circuit after the motorstarts and is running, etc, which may possibly ruin the compressormotor.

SUMMARY OF THE INVENTION In accordance with the present invention, ithas been found that the aforenoted prior art problems can be overcomewith a novel, factory-assembled auxiliary starter device which providesfield installation personnel with accurate, quickly installed means foradding extra capacitance to the starting circuit of the electric motorfor the fluid compressor of an air conditioner. Basically, the presentinvention comprises: auxiliary capacitor means; auxiliary switchingrelay means; auxiliary conductor means electrically interconnecting theauxiliary capacitor and switch relay means; base means mounting theauxiliary means and being adapted for ready attachment and detachment toand from cabinet means housing the compressor; and plug meanselectrically connected to the auxiliary conductor means and readilyengageable and disengageable to and from complementary plug meanselectrically connected to the compressor motorstartingcircuit to quicklyelectrically connect and disconnect the auxiliary means to and from thecompressor motor starting circuit.

BRIEF DESCRIPTION OF THE DRAWING The present invention is illustrated inthe accompanying drawings, wherein:

FIG. I is a side elevational view of the condenser-compressor sectionofa typical, modern air conditioner cooling unit of the so-calledsplit-system variety incorporating a presently preferred form of theauxiliary starting device of the present invention, with portions of thesection cabinet and the compressor housing being broken away andelements normally enclosed by the removable top cover of the cabinetbeing shown in shadow;

FIG. 2 is an enlarged fragmentary top plan view of the condenser-compressor section illustrated in FIG. 1, with the cabinet beingrotated leftward about the vertical axis and the cabinet top coverremoved;

FIG. 3 is a still further enlarged fragmentary elevation perspectiveview of FIG. 2 and illustrates the means provided for the readyattachment and detachment of the auxiliary starting unit to and from thecabinet and for its quick electrical connection and disconnection to andfrom the compressor motor circuit; and

FIG. 4 is a schematic wiring diagram showing the electric circuit forthe auxiliary starting device illustrated in FIGS. 1-3 and itsrelationship to compressor motor circuit.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing andparticularly to FIG. I thereof, there is illustrated acondenser-compressor section 10 of a typical air conditioner coolingunit of the so-called splitsystem variety. The condenser-compressorsection 10 comprises a generally rectangular, hollow boxlike cabinet IIwhich includes a lower portion 12 that rests atop a concrete pad 13which is provided outside the building (not shown) that is to be cooled,and removable cover portion I4. The cabinet lower portion 12 includesfour vented, generally vertical side walls 15 and a generally horizontaltop wall 16 (partly shown in FIGS. 2 and 3) that is perforated by alarge generally circular central opening 17.

As illustrated in FIG. 1, there are housed within the cabinet lowerportion l2, among other things, a condenser 18 and compressor 19. Thecondenser 18 is of a well-known type and comprises a finned tube coiledaround the interior of the vented side walls 15 of the cabinet lowerportion 12. The compressor 19 is a well-known hermetic type and includesa generally vertically arranged hollow cylindrical housing 20 whichcontains an electric motor 21 in its upper portion and a reciprocatingtype pump 22 in its lower portion. The compressor motor 21 includes astator 23 and a rotor 24 and, as shown schematically in FIG. 4, itsstator 23 includes a start winding 23s and a run winding 23r. Thecompressor pump 22 includes a cylinder block 25 having at least onepiston 26 housed therein which is reciprocated by a piston rod 27 thatis connected to a crank shaft 28 which is, in turn, connected to themotor rotor 24 in a well-known manner.

The compressor 19 has its discharge outlet 30 located at the lower endof its housing 20 and fluid connected to a conduit 31 which extendsoutward through an opening 32 provided in one of the sidewalls 15 of thecabinet lower portion 12. The condenser coil 18 has its discharge endconnected by another conduit 33 to the compressor inlet 34 provided atthe top of the compressor housing 20, while the opposite or inlet end ofthe condenser coil 18 is fluid connected to yet another conduit 35 whichextends outward though the cabinet opening 32 generally parallel to theouter end of the conduit 31 that is fluid connected to the compressordischarge outlet 30. It is to be understood that the parallel outer endsof two conduits 31 and 35 can be readily fluid connected by well-knownmeans (not shown) to the inlet and outlet ends, respectively, of theevaporator coil (not shown) which is contained within the building (notshown) that is to be cooled.

As further shown in FIG. 1, the cabinet lower portion 12 also supports afan 36 which circulates outdoor air across the condenser coil 18. Thefan 36 includes its own electric motor 37 which is supported generallyvertically within the opening 17 in the top wall 16 ofthe cabinet lowerportion 12 by spider means or the like (not shown). And, the fan 36 alsoincludes an impeller 38 mounted on a rotary output shaft 39 that extendsupwardly from the fan motor 37.

The cabinet cover portion 14 includes a top wall 40 having a screened,generally circular opening 41 and four downwardly extending sidewalls42. The screened central opening 41 overlies the fan impeller 38 andlower edges of the cover portion sidewalls 42 fit snugly around theupper edges of the four sidewalls of the cabinet lower portion 12 andare attached thereto by removable fastener means, such as sheetmetalscrews 43. When installed over the top of the cabinet lower portion, asshown in FIG. 1, the cabinet cover portion 14 encloses the condenser fanimpeller 38 and also covers certain electric control means that areprovided for the compressor motor 21 in particular accordance with thepresent invention and will be described in detail hereinafter. As shownin FIG. 1, these compressor motor control means include standard controlmeans 50 mounted on the left front portion of the top wall 16 of thecabinet lower portion 12 and an auxiliary starting device 70 which canbe readily attached to the right front portion of the top wall 16 of thecabinet lower portion 12, if required.

As best shown in FIGS. 2-4, the standard compressor motor control means50 comprises a first or standard capacitor 51,

which is attached to the top wall 16 of the cabinet lower portion 12 bya clamp 52 that is fastened thereto at its opposite ends, and apolarized electric plug 53 which includes a female portion 53f and aremovable male portion 53m (FIG. 3). The female portion 53f of the plug53 has four socketlike terminals 54, 55, 56 and 57, two of which 55 and56 are particularly adapted to receive a pair of pronglike terminals 58and 59 that are provided on the male portion 53m of the plug 53 and areelectrically interconnected by conductor 60.

In accordance with the present invention, it is intended that thecondenser-compressor section 10 will be shipped from the factory withthe female and male portions 53f and 53m of the polarized electric plug53 joined together and having the pronglike terminals 58 and 59 of themale plug portion 53m inserted into and electrically convected with thesocketlike terminals 55 and 56 ofthe female plug portion 53f. With thisfactory-shipped, standard arrangement, as shown schematically in FIG. 4,the standard capacitor 51 and the compressor motor stator start winding23s are connected in electrical series across a pair of main powersupply lines L, and L by circuitry which also includes an internalcurrent overload protector device 23;; mounted adjacent the compressormotor stator 23 and a pair of main power disconnect relays 61 and 62.More specifically, one 61 of the two main power disconnect relays 61 and62 has its first terminal 61a electrically connected to the first mainpower supply line L,, while its second terminal 61b is electricallyconnected by a conductor 63 to the first terminal 51a of the standardcapacitor 51. The second terminal 51b of the standard capacitor 51 iselectrically connected to one 55 of the two socketlike terminals 55 and56 of the female portion 53fof the polarized plug 53 by a conductor 64,while the other 56 of these two socketlike terminals 55 and 56 isconnected to the first terminal 23st: of the compressor motor statorstart winding 23s by a conductor 65. Another conductor 66 electricallyconnects the second terminal 23sb of the compressor motor stator startwinding 23s to the first terminal 23pa of the internal current overloadprotector device 23p, while yet another conductor 67 electricallyconnects the second terminal 23pb of the internal current overloadprotector device 23p to the first terminal 62a of the other one 62 ofthe pair of main power supply disconnect relays 61 and 62. Finally, thesecond terminal 62b of the second disconnect relay 62 is electricallyconnected to the other main power supply line L,. And, as further shownin FIG. 4, the compressor motor stator run winding 23r is connected inelectrical parallel with the series-connected standard capacitor 51 andcompressor motor stator start winding 23s by having its first terminal23m electrically connected by a conductor 68 to the second terminal 611;of the first main power disconnect relay 61 and its second terminal 23rbelectrically connected to the second terminal 23sb of the compressormotor stator start winding 23s. It should also be noted that, for areason that will subsequently be apparent, the socketlike terminal 54 ofthe female portion 53f of the polarized plug 53 is electricallyconnected by a conductor 69a to the second terminal 61b of the firstpower disconnect relay 61 and the socketlike terminal 58 of this femaleplug portion 53f is electrically connected by another conductor 69b tothe first terminal 62a of the second power disconnect relay 62.

With the aforedescribed circuitry and with the female and male portions53f and 53m of the polarized electric plug 53 joined together and havingthe pronglike terminals 58 and 59 of the male plug portion 53m insertedinto and electrically connected with the socketlike terminals 55 and 56of the female plug portion 53f, it can be seen that there will be twoelectric current paths between the main power lines L, and L and throughthe compressor motor stator 23 when the disconnect relays 61 and 62 areclosed. The first of these two current paths will pass from the firstpower line L, through the first disconnect relay 61' and then,respectively, through the conductor 63, the standard capacitor 51, theconductor 64, the socketlike terminal 55, the pronglike terminal 58, theconductor 60, the pronglike terminal 59, the socketlike terminal 56, theconductor 65, the start winding 23s, the conductor 66, the internalcurrent overload protector device 23p, the conductor 67, and the seconddisconnect relay 62 and into the second power supply line L And, ofcourse, the second of these two current paths will pass from the firstpower supply line L, through the first disconnect relay 61 and then,respectively, through the conductor 68, the stator run winding 23r, theconductor 66, the internal current overload protector device 23p, theconductor 67, the second disconnect relay 62 and into the second mainpower line L Typically, the sizing of the standard capacitor 51 that isprovided in the condenser-compressor unit 10 at the factory will beapproximately 10 microfarads per horsepower of the compressor motor 21.Thus, a 30-microfarad capacitor would be utilized for thefactory-installed standard capacitor 51 in a condenser-compressorsection 10 employing a compressor 19 having a 3-horsepower motor. Or, a40-microfarad capacitor would be utilized for the standard capacitor 51in a condensercompressor section a 4-horsepower motor for the compressormotor 21; etc.

It should, of course, be understood that only the standard control group50 will be installed on the condenser-compressor section 10 at thefactory, since this should provide sufficient capacitance to start thecompressor motor 21 if the condenser-compressor section 10 is connectedin the field to a modern evaporator section. However, as previouslynoted, it is not infrequently desired to interconnect a modernreplacement condenser-compressor section 10 with an old evaporatorsection. And, for the reasons previously noted, the capacitance providedby the factory-installed standard capacitor 51 will be sufficient tostart the compressor motor under these replacement combinationconditions.

In the past, various schemes have been improvised by field installationpersonnel in an effort to overcome the aforenoted incompatibilitybetween a modern replacement condenser compressor section and an oldevaporator section with which it is sought to be coupled. However, theseprior art methods have required field rewiring of the replacementcompressor motor circuit. And, such field rewiring has presentedproblems, e.g. use of oversized auxiliary capacitors, failure to providemeans for disconnecting the auxiliary capacitor from the circuit afterthe compressor motor starts and is running, etc. which may possibly ruinthe compressor motor. However, it has been found that the aforenotedprior art problems can be overcome by the novel factory assembledstarter device 70 of the present invention which provides fieldinstallation personnel with accurate, quickly installed means for addingextra capacitance to the starting circuit of the electric motor 21 ofthe fluid compressor 19 of the condenser-compressor section 10 of an airconditioner cooling unit of the so-called splitsystem variety.

As illustrated, the auxiliary starter device 70 of the present inventioncomprises base means including a base bracket 71 that is perforated witha plurality of fastener receiving openings 72a which are adapted to bereadily aligned over complementary fastener receiving openings 72b thatare performed at the factory in the right front portion of the top wall16 of the cabinet lower portion 12 (as seen in FIG. 1) and readilyattached to and detached from the top wall 16 by removable fastenermeans, such as the plural sheetmetal screws 720, which are received inthe aligned openings 72a and 72b. As best shown in FIGS. 2-4, thebracket 71 mounts auxiliary capacitor means including an auxiliarycapacitor 73; auxiliary switch relay means 74 including a normallyclosed switch 74r that can be opened upon actuation of a current levelsensitive solenoid 74s; auxiliary current overload protector meansincluding a current overload protector device 75; and auxiliaryconductor means for electrically interconnecting the auxiliary capacitormeans 73, auxiliary switch plug means including an auxiliaryoverloadprotector device 75. The auxiliary starter device 70 furthercomprises auxiliary plug means including an auxiliary male plug 76m thatis adapted for quick connection to and disconnection from the femaleportion 53f of theaforedescribed polarized electric plug 53, uponremoval of the male portion 53m of the polarized plug 53 therefrom. Thisauxiliary plug 76m has four pronglike terminals 78, 79, 80 and 81, afirst pair 79 and 80 of which are particularly adapted to berespectively received in two 55 and 56 of the socketlike terminals 54-57of the female portion 53f of the polarized plug 53, and a second pair 78and 81 of which are particularly adapted to be respectively received inthe other two socketlike terminals 54 and 57 of the female portion 53fof the polarized plug 53.

In accordance with the present invention, the auxiliary capacitor 73,the auxiliary switch relay means 74 and the auxiliary current overloaddevice 75 are accurately selected at the factory to provide the correctextra starting capacitance for a condenser-compressor section having acompressor motor 21 of a particular horsepower rating, and they are thenpreattached to the base bracket 71 and prewired to one another and tothe auxiliary plug 76m at the factory. To this end, factory personnelselectthe proper sized auxiliary capacitor 73, auxiliary switch means 74and auxiliary current overload protector device 75 and permanentlyattach them to the base bracket 71. As illustrated in FIGS. 2 and 3, theauxiliary capacitor 73 is attached to the base bracket 71 by a clamp730, which is, in turn, permanently secured to the base bracket 71 bywelding or other suitable fastening means. And, the auxiliary startingrelay means 74 and the auxiliary current overload protector device 75are respectively attached to mounting brackets 74c and 75c, which are,in turn, permanently secured to the base bracket 71 by welding or othersuitable fastening means.

Then, the following prewiring (best shown in FIG. 4) is performed at thefactory. The first terminal 73a of the auxiliary capacitor 73 iselectrically connected by a conductor 82 to the pronglike terminal 78 ofthe auxiliary male plug 76m, while its second terminal 73b is connectedby a conductor 83 to the first terminal 74m of the normally closedauxiliary switch relay 74r. The second terminal 74rb of the normallyclosed auxiliary switch relay 74r is connected by a conductor 84 to thefirst terminal 74sa of the solenoid 74s of the auxiliary switch relaymeans 74, while the. second terminal 74sb of the solenoid 74r isconnected by a conductor 85 to the pronglike terminal 81 of theauxiliary male plug 76m. The second terminal 74rb of the normally closedauxiliary switch relay 74r is also electrically connected by a conductor86 to the pronglike terminal 79 ofthe auxiliary male plug 76m. And, thefirst terminal 74m of the solenoid 74s is connected to the firstterminal 75a of the auxiliary current overload protector device 75 byconductor 87, while the second terminal 75b of the auxiliary currentoverload protector device 75 is connected by a conductor 88 to thepronglike terminal 80 of the auxiliary male plug 76m.

Now, assuming field installation personnel have interconnected a moderncondenser-compressor section 10 with an old previously-installedevaporation section (not shown) or that for some other reason thecompressor motor 21 of the condenser-compressor unit 10 will not startas shipped from the factory, they may quickly and easily solve thisproblem by performing the following steps:

l. procuring an auxiliary starter device of the present invention whichis sized for use with the particular horsepower rating of the compressormotor 21 that has been factory-installed in the condenser-compressorsection 10 (several assorted sized should be carried on their servicetruck);

2. removing the sheetmetal screws 43 from the cabinet cover 14 and thecover 14 from the cabinet bottom portion 12;

3. aligning the fastener receiving openings 72a in the base bracket 71of the auxiliary starter device 70 with the fastener receiving openings72b in the top wall 1670f the cabinet lower portion 12 and theninserting the sheetmetal screws 720 which are provided with theauxiliary device 70;

4. disconnecting the factory-installed male portion 53m from the femaleportion 53f of the polarized plug 53 of the standard motor control means50; r

5. connecting the auxiliary male plug 76m of the auxiliary startingdevice 70 the female portion 53f of the polarized plug 53, with thepronglike terminals 78, 79, 80 and 81 being respectively inserted intoand electrically connected to the socketlike terminals 54, 55,56 and 57.

Having done this, it can best be seen by reference to FIG. 4

that closure of the two main power disconnects 61 and 62 will initiallycause current to flow between the power lines L and L, and through thecompressor motor stator start winding 23:

via both the standard capacitor 51 and the auxiliary capacitor 73, whichwill then be electrically paralleled with one another and connected inelectrical series to the compressor motor stator start winding 23sthrough the auxiliary current overload protector device Thus, duringthis initial or starting period, the capacitance in the circuit for thecompressor motor stator start winding will equal the sum of thecapacitive values of the standard capacitor 51 and the auxiliarycapacitor 73. And, during this initial period, there will also be a flowof current through the solenoid 74s and, when (usually within 10 secondsafter closure of the disconnect switches 61 and 62) the intensity ofthis current flow becomes sufficient to actuate the solenoid 74s to openthe normally closed auxiliary switch relay 74r, the opening of theauxiliary switch relay 74r will then, of course, stop the flow ofcurrent through the auxiliary capacitor 73. However, in the event thatthe auxiliary switch relay means 74 should malfunction and the switchrelay 74r remain closed after the compressor motor 21 is started andrunning, the auxiliary current overload protector device 75 is sized toopen thus stop all current flow across the compressor motor stator startwinding 23s and thus avoid destruction of the motor 21.

It should be apparent to those skilled in the art that while there hasbeen described what, at present, is considered to be a presentlypreferred embodiment of this invention in accordance with the disclosedapparatus without actually departing from the true spirit and scope ofthis invention. For example, the auxiliary start device 70 of thepresent invention obviously could also be used to provide extracapacitance in the starting circuit of the compressor motor for an airconditioner of the heat pump variety. It is, therefore, intended thatthe appended claims shall cover such modifications and applications thatdo not depart from the true spirit and scope of the present invention.

What is claimed is:

I. An auxiliary starter device for quickly and accurately providingextra capacitance in the starting circuit of the electric motor for thefluid compressor of an air conditioner comprising:

a. auxiliary capacitor means;

patent statutes, changes may be made to theb. auxiliary switching relaymeans;

0. auxiliary conductor means electrically interconnecting said auxiliarycapacitor and switch relay means;

d. base means mounting said auxiliary means and being adapted for readyattachment and detachment to and from cabinet means housing thecompressor; and

e. plug means electrically connected to said auxiliary conductor meansand being readily engageable and disengageable to and from complementaryplug means electrically connected to the compressor motor startingcircuit to quickly electrically connect and disconnect said auxiliarymeans to and from the compressor motor starting circuit.

1. An auxiliary starter device for quickly and accurately providingextra capacitance in the starting circuit of the electric motor for thefluid compressor of an air conditioner comprising: a. auxiliarycapacitor means; b. auxiliary switching relay means; c. auxiliaryconductor means electrically interconnecting said auxiliary capacitorand switch relay means; d. base means mounting said auxiliary means andbeing adapted for ready attachment and detachment to and from cabinetmeans housing the compressor; and e. plug means electrically connectedto said auxiliary conductor means and being readily engageable anddisengageable to and from complementary plug means electricallyconnected to the compressor motor starting circuit to quicklyelectrically connect and disconnect said auxiliary means to and from thecompressor motor starting circuit.
 2. The invention of claim 1, furtherincluding auxiliary current overload protector means mounted on saidbase means and electrically interconnected with said auxiliary capacitorand switch relay means by said auxiliary conductor means.
 3. Theinvention of claim 2, further including fastening receiving meansprovided on said base means and being readily alignable withcomplementary fastener receiving means provided on the cabinet means. 4.The invention of claim 1, further including fastener receiving meansprovided on said base means and being readily alignable withcomplementary fastener receiving means provided on the cabinet means.